Hydraulic control for variable speed transmissions



11111111101110 CONTROL. FOR VARIABLE SPEED- TRANSMISSIONS Filed April 8, 1935 JJ :2. MIN

O INVENTOR 3:956, -{rp E 63 garr y 0. Clay,

ATTORNEYS Patented Mar. 22', 1938 [PATENT-II OFFICE mar time CONTROL Fon VARIABLE 'SPEED TRANSMISSIONS Harry OI Clay, Columbus, Ind., assignor to Reeves Pulley Cmpany,'-Oolumbils, Ind., a, corporation of Indiana Application April 8, 1935, Serial No. 15,210

2 Claims.

I I i The present application relates o hydraulic controls, primarily intended for controlling variable speed transmissions of the well-known Reeves type. A primary object of the inven-:

tion is to provide means whereby the power delivered by a constantly operating motor may be v utilized,' as required, to adjust the ratio between input speed and output speed of such a transmission. A further object of the invention is to improvehydraulic controls, generally. A further' object of the invention is to provide, in an organization of the character indicated, particularly effective means whereby the operation of the control is utilized to bring the control to rest .after exactly the required degree of adjustment ,of the transmission elements has been effected,

Further, objects of the invention will appear as the description proceeds.

To the accomplishment of the above and relatedIobjects, my invention may be embodied in the .form illustrated in the accompanying draw- 'ing, attention being called tothe fact, however,

.thatthe drawing is illustrative only, and that I change may be made in the specific construction illustrated anddescribed, so long-as the scope of the appended claims is not .violated.

Fig. 1 is a more or less diagrammatic representation of the control of the present application applied to a'Reeves variable speed transmission;

Fig. 2 is a plan view of the control, the cover for the housing having been removed, and parts having been broken away for clarity of illustra tion;

Fig'.. 3 is motor which forms an element of the invention,

parts of the casing having been broken away;

Fig. 4 is a horizontal sectio'n,'on an enlargod" scale,,through the controlvalve casing; Fig. 5 is a vertical section through the control valve, parts of the valve bushing being shown in shaft, the other being the output shaft; Two

coned disks i3 and I! are axially slidably splined on the shaft 1 I, said disks cooperating to form an 55 expansible V-pulley. Similarly two coned disks a'perspectlv'e view'of thehydrau lic' l5 and it are axially slidably splined on shaft l2.- A pair of levers l7 and I8, suitably pivoted intermediate their ends, are connected tothrust bearings associated with the respective disks l3, l4, l5 and IS, the arrangement being such that when 5 corresponding ends of the two levers l1 and II! are movedt'oward each other, the adjacent cones are likewise moved toward each other; the oppo- I site ends of the lever, and the cones associated therewith, being correspondingly moved away 10 from each'other.

A belt IQ of V-cross-section'provides the driving connection between the pulley formed by the disks l3 and I4 and by the pulley formed by the disks l5 and it. Y 15 With the parts in the position illustrated and if it be assumed that shaft II is the input shaft, I

it will be obvious that the shaft I! will be driven at a speed much greater than the speed of the shaft II. If, however, the cones?" and ll are 20 separated and the cones l5 and I6 are correspondingly moved toward each other, the dinerence in speed will be reduced; and it is a characteristic of this type of transmission that, in'the extreme position of the parts oppfisite the posi- 25 tion. illustrated, there will be a. speed reduction from, the shaft H to the shaft l2 substantially equal to the speed increase effected when the parts are arranged in the manner illustrated in Fi 1. so

The shaft ll carries a pulley Land the shaft 12 carries a pulley 2|, whereby power may be. applied to the transmission and withdrawn therefrom; r The reference numeral 22 'indicates a shaft which, within the boundaries of the frame Ill. is threaded, the parts of the thread adjacent .the opposite ends of the shaft being of opposite pitch. A guide rod 23 has slidingly mounted thereon.

sleeves 24 and 25 which are carried'on nuts (not 40 shown) threadedly received on said portions of the thread of the shaft 22. It will be seen that a driving connection is provided between the sleeves 24 and 25 and the adjacent ends of the I respective levers l1 and I8. Thus, rotation of 5' theshaft 22 in one direction will move the disks I 5 and I6 toward eachother and will movethedisks I3 and I4 away from each other; while rotation of the shaft 22 in the opposite direction will'have an opposite effect upon the disks l3, ll, l5, and 5 '16. The manner in which the shaft 22 causes motion of the discs 13, L15 and I6 isvery clearly illustrated in a large number of patents, among which are Patents Nos. 583,402; 603,067; 1,923,- 041; 2,035,402; and 2,084,723. In view of this fact, and in view of the further fact that the manner of operation of Reeves variable speed cent the transmission. -To the outer wall of said housing is, in the preferred embodiment of my sprocket 3| on the shaft 32 of a pump 33, preferably of the gear type. The housing 26 formsa reservoir for oil, or other suitable fluid, into which projects an inlet pipe (not shown) leading from the inlet of the pump 33. A pipe 36 leads from the discharge port of the pump to a T 35, to one branch of which is connected a pressureregulating relief valve 36 provided with a stem 31 for adjusting the pressure at which said valve will open to discharge oil into the reservoir. To the other branch of the T 35 is connected a pipe 38 leading to the inlet port 39 of a valve casing 40. Said valve casing 40 is provided with separate outlet ports 4| and 42, and a pipe 43 leads from the port 4| to one inlet port 45 of a reversible fluid motor 41, while a pipe 44 leads from outlet port 42 to the other inlet port 46 of said motor 41. The shaft 48 of motor 41 projects outwardly through the 'wall of the housing 26 and carries, outside said housing, a

sprocket 49 which is connected, by a chain 50,

to drive a sprocket 5| mounted on the shaft 22.

Obviously, operation of the motor 41 in one direction will drive the shaft 22 in a direction such as to move the disks l5 and I6 toward each other; and operation of the motor 41 in the opposite direction will drive the shaft 22 to move the disks l5 and I6 away from each other.

and act to limit the stroke of the valve member.

69 to about two-thirds the width of the ports 60 and 65.

Adjacent to its longitudinal center, the bushing 54 is provided with an external groove 51 from the bottom of which a plurality-of ports 58 open into the interior bore of said bushing. Said groove 51 registers with the inlet port 39 of the valve casing .40, whereby the interior of the bushing 54 is placed in communication with said port. A second groove 59 is formed in the external surface of said bushing 54, said groove registering with the port 4| of the valve casing 40; and a plurality of ports 60 open from said groove 59 into the bore of the bushing 54, thereby placing said bore in communication with the port 4|. At a point between said groove 59 and the adjacent end of the casing 40, said casing is formed with an internal groove 6|, with which register a plurality of ports 62 opening into the bore of the bushing 54; and said groove 6| registers with an exhaust port 63 formed in the casbushing 54 and registers with the outlet port 42 of the casing 40. A plurality of ports 65 connect the groove 6% with the interior of the bushing 5t. Betweenthegroove '65 and the adjacent and .ofthe.casingflksziid casingis formed with an internal groove 66 with which register a plurality of ports at opening into the bore of the bushing and said groove 85 registers also with a sec-.

ond exhaust port 68in the casing 46 opening into the reservoir of the housing 26.

' Reciprocably mounted in the bore of the bushing 56 is a valve member 69 of the piston type 1 provided with a plurality of heads 18, iii, 12, and

As is clearly shown, one end of the valve- '13. member 69 projects fromthe casing 46.

A pair of links 15 connect said valve 69 with an arm 16 which carries a collar- 11 operating to hold in place on said arm a beveled gear 18 which is free to rotate on said arm 16 but is'held against reciprocation thereon. At its base, said arm 16 is provided with a hub 19 journaled on a rock shaft which is suitably supported in bearings provided on a plate 8| which is secured to the housing 26.

Secured to the rock shaft 86 is a beveled pinion 82 meshing with the gear 18. Journaled on the rock shaft 80 is a second beveled pinion 81 meshing also with the gear 18 at a point diametrically opposed to the point of engagement between the gear 18 and the pinion 82., An arm 88 is secured to the pinion 81.

The rock shaft 80 carries also a lever 83 having an extension 84 secured thereto through a strain-relieving connection indicated generally at 85. Said connection 85 is of known construction and forms no part of my present invention; and is, therefore, not described in detail. If desired, a cable 86 may be .attached to the extension 84, whereby said extension may be operated automatically from a driven machine, or may be operated from a point of remote control.

To the arm 88 is secured a rod 89 connected, at

its opposite end, to the sleeve 24.

In practice, the transmission indicated generally at I0 is used to transmit power from any suitable power source to a driven machine, and is capable of manipulation to vary the speed of the driven machine though the source of poweroperates at constant speed. If it be assumed that power is being supplied to the shaft II and is being taken off to the driven machine from the pulley 2|, and if it be assumed that the motor -21 is running and that the valve member 69 is in the position illustrated in Figs. 4 and 5, it will be seen that power will be transmitted, with a certain speed increase, at constant speed so long as the parts remain in such positions. Since the motor 21 is operating, the pump 33 is operating to force oil from the reservoir in the housing 26 through the pipe 34 to the T 35. With the valve 69 in the position illustrated, the liquidunder pressure can only flow through the ports 39 and 58 into that portion of the bore of the bushing 54 embraced between the valve heads 1| and 12. Pressure, therefore, builds up between the pump and the valve casing 40 until the valve 36 will open to discharge the supplied oil back into the reservoir.

If, now, the extension 84 is moved slightly to be transmitted through: the pinion-82 to the gear I8 to move said gear 18 and arm 16 in a counterclockwise direction about the axis of the shaft 89. There will also be a. slight rotation of the gear 18 about its own axis, and it is for that reason that said gear is journaled on the arm 16 instead of being rigidly secured thereto.

Such movement of the arm 16 will shift the valve member 69 toward the left as viewed in Figs. 4 and 5, thereby placing that portion of the interior of the bushing 54 embraced between the heads II and 12 in communication with the ports 65;, and placing that portion of the interior of the bushing 54 embraced between the heads I2 and 13 in communicationwith the ports 60.

Liquid will now flow through the pipe 34, T 35,

pipe 38, port 39, groove 51, ports 58, bushing 54, ports 65, groove 64, port 42, and pipe 44 to theinlet 46 of the motor 41. As the liquidflows past the blades 90 and 9| of said'motor, it will cause clockwise rotation of the shaft 48 as viewed in Fig. 1; and such rotation .will be transmitted through the chain 50 to the shaft 22. From the motor 41, the liquid will flow through the port 45, pipe 43, port 4|, groove 59, ports 60, bushing-54, ports 62, groove 6i, and port 63, back into the reservoir in thehousing chamber 26. g

Clockwise rotation of the shaft 22 will be transmitted through the'sleeves 24 and 25 to move the disks l5 and I6 toward each other and to continued until, andv only until, the resultant adjustment of the, transmission members has continued far enough to return the arm 'lfiand valve 69 to neutral position. It will be noted that such return movement of the valve 69 to neutralposition does'not affect the lever 83 and extension .84; and that, therefore, the position of the said extension 84 may well constitute an indicator of the speed ratio of the transmission, at any given moment.

I claim as my invention:

1. For use with a variable speed transmission including an element movable to vary the ratio between the input speed and the output speed thereof, a control mechanism comprising a reversible fluid motorhaving two fluid inlets, a source of fluid under pressure, a conduit conmeeting said source to supply fluid to one of said motor inlets to drive said motor in one direction, a conduit connecting said source to supply fluid under pressure to the other of said motor inlets to drive said motor in the opposite direcof said motor inlets and shiftable' in the opposite direction from neutral position to direct fluid flow to the other of said motor inlets, means connecting said motor to drive the movable element of the transmission in opposite directions, a rock shaft, a ,bevelled pinion fast on said rock shaft, an arm angularly related to said rock shaft, oscillable about the axis of said rock shaft, and operatively connected tosaid valve, a bevelled gear loosely mounted on said arm and meshing with said bevelled pinion, a second bevelled pinion loosely -mounted on said rock shaft and meshing with said bevelled gear, and means operatively connecting said element-driving means to rotate said second bevelled pinion..

.2. In a device of the class described. areversible fluid motor having two fluid inlets, a source 'of fluid under pressure, conduit means leading from said source to said respective inlets, valve means connected in said conduit means for controlling flow therethrcugh, and comprising a member shiftable in one direction from a neutral position to direct fluid flow to one of said motor inlets to drive said motor in one direction and shiftable in another direction from a neutral position to direct-fluid flow to the other of said motor inlets to drive said motor in the opposite direction, a shaft, two pinions mounted on said shaft, one of said pinions being fast on said shaft and the other being rotatable with respect thereto, an arm oscillably mounted on said shaft and operatively connected to said shiftable member, a gear rotatably mounted on said arm and meshing with said pinions, means for turning said shaft, and means operatively con- 

